Material working apparatus



Dec, 20, 1938. E. J. SVENSON MATERIAL WORKING APPARATUS 11 Sheets-Sheet1 h 5 .WN ill. 3 r W Q wfl. was 4 7% Q J Yoko: w U m ixmqhw QN Q U P QMW F E E l E: m

Filed Jan. 23, 1934 Dec. 20, 1938. I E. J. SVENSON 2,140,565

v I MATERIAL WORKING APPARATUS Filed Jan. 23, 1954 11 Sheets-Sheet 2DecQZO, 1938. v E J. SVENSON v2,140,565

MATERIAL WORKING APiARATUS Filed Jan. 23, 1934 ll Sheets-Sheet 4 Deg.20, 1938. E. J. SVENSON MATERIAL WORKING APPARATUS Filed Jan. 23, 1954ll Sheets-Sheet 5 ZIP/beat Qs R RN m l I! f, m JEN J; A .r, o a 6 gm m bww m .mfiw V E. J. SVENSON MATERIAL WORKING APPARATUS Dec. 20, 1938.

Filed Jan. 23, 1934 11 Sheets-Sheet 6 liwantor I" si J'Suensom 1 9 W W5ms gm \N W, uGN NE A NQN A Dec. 20, 1938.

E. J. SVENSON MATERIAL WORKING APPARATUS Filed Jan. 25, 1954 llSheets-Sheet 7 lIIlIIIIIII/III'IIIIII,

1938- I E. J. SVENSON 2,140,565

MATERIAL WORKING APPARATUS Filed Jan. 23, 1934 11 Sheets-Sheet a Dec.20, 1938. E J SVENSON 2,140,565

MATER IAL WORK ING APPARATUS Filed Jan. 25, 1934 ll Sheets-Sheet 9 AU33&

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III/II/I/IIIII/ VII/II/I/I/I/I/II/I/III/l 11 Sheets-Sheet l0 WNQN Q? E.J. SVENSON MATERIAL WORK ING APPARATUS Filed Jan. 23, 1934 Dec. 20,1938.

Patented Dec. 20,1938 2,140,565

UNITED STATES PATENT OFFICE MATERIAL WOBKING APPARATUS Ernest J.Svenson, Rockford, 111.

Application January 23, 1934, Serial No. 707,934 125 Claims. (01. 82-48)This invention relates generally to material determined range because ofcertain structural; working apparatus, and more particularly tomalimitations in the machine proper, and it is one chine tools and tohydraulic and electrical conof the important objects of the presentinvention t'rolstherefor. It is well established that adto provide amachine wherein spindle rotation 6; vancements made in various arts-forexample, may be increased far above the speeds attained .the art ofmachine tools and the likefrequently .in conventional machines withoutsubjecting the result from the fact that the work to be perwork to thehazards of inaccuracy or other imformed in the production of a newarticle or 'perfections resulting from vibrations and the device ofmanufacture is incapable of being satislike. To this end I propose toprovide a machine 10 factorily accomplished by conventional mawherein aheavy duty spindle may, in fact, be 10 chines. In other words, necessityis often the rotated at speeds ranging from approximately forerunner ofinvention. However, unless the 50 R. P. M. to 4,000 R. P. M., and toequip the mechanism constructed in accordance with the machine withcontrol mechanism whereby this I idea of meeting the need therefor,proves satisrange of operation may be accomplished with H factory-fromthe standpoint of practical applisafety without introducingdeleterious'vibrations,

cation in the field, the public receiveslittle 0r etc. no benefit.Another problem with which machine tool This is particularly true in theart of machine builders have been confronted for many years tool designwherein machines are constantly beis that of directly coupling a primemover-such developed for t e pu p se of per ormi g opas an electricmotor-in line with a spindle; for 2 erations necessitatedby the inherentnature of example, the spindle of a lathe. My invention the workpiece,and hence the work to be percontemplates a machine whereby this directcouformed thereon. pling is accomplished, and wherein the speed of Thedevelopment of new high speed cutting a spindle and the feed of themachine may vary tools, such as tools comprised of tungsten carbide overa range heretofore considered as being im- 26 and other alloys, hasenabled cutting operations possible, at least from a practicalviewpoint. to be performed at much greater speeds than Morespecifically, it is an object of my in- Were formerly possibleviouslythis increase vention to provide a machine as above set forth in cuttingspeed, coupled with the ability to make wherein the mechanism forimparting feeding 30 heavier cuts by such tools, requires thedevelopmovement to a tool carriage or the like is s'yn- 30 ment ofmachines which will withstand the trechronized with the prime moverwhich propels mendous strains and stresses incident to these the spindleover the above mentioned wide range cutting operations. It is fair tosay that the apof speeds, and to this end I provide an improvedplication of these high speed tungsten carbide practical controlarrangement whereby the wide tools over a broader range of use in thefield is range of spindle speeds in synchronism with the 35 dependentupon the ability of machine tool buildrange of carriage feed will takeplace without ers to provide machines which will successfully theintroduction of shocks, vibration; and the withstand the forces set upwhen these tools are like. employed. That is to say, such machines,under Still more specifically, the invention contem- 40 the abovementioned heavy duty conditions, must plates the synchronizing of apropelling mecha- 40 not become distorted as a result of the action,nism-such as a feed pump-with the prime of unbalanced forces and thelike. In other mover coupled with the spindle without the use words, anaccurate machining operation must of mechanical couplings, and to thisend I protake place, even though the tool is cutting at a pose to employelements of a driving arrangemuch higher rate of speed and is making amuch ment which is commonly referred to by engineers heavier cut in thework. It is, therefore, one as the selsyn drive. I contemplate the useof of the important objects of the present invention the prime mover ormotor which drives the spinto provide a machine tool which isparticularly die for propelling a generator, and this genadapted towithstand severe or heavy duty opererator is electrically coupled. witha motor, which ating conditions, and to enable the rapid and provides aprime mover for a propelling mecha- 5i accurate machining of a workpiece while opernism, such as a feed pump. In this manner the atingunder such conditions. propelling mechanism or feed pump which serves-Heretofore high speed operation-for example, to propel a machinecarriage is synchronized the high speed rotation of a work supportingwith'the spindle, and said spindle may vary in M spindle in a lathe-hasbeen held within a prespeed over a very wide range without in any way 1,

subjecting the pump to severe strains and stresses.

It is another object of my present invention to provide in a machine ofthe type set forth above an improved mounting for the spindle, whichmounting is designed to withstand the severe forces set up when thespindle is operating at high speeds. The mounting of the spindlecontributes materially in providing a rigid support for heavy workpieces rotating at high speeds, and thereby enables cutting toolssuch astungsten carbide, diamonds, and the liketo accurately machine the workand positively preclude distortions which might otherwise result.

More specifically, the invention contemplates a spindle support whereinan anti-friction bearing of special design is provided at the worksupporting end of the spindle to take up radial loads, and a specialanti-friction bearing is provided at the driven end to take up bothradial load and end thrust, said parts being specially designed tooperate under high speed conditions without overheating. I

A further object of the invention is to provide a machine as set forthabove, wherein the electric motor or prime mover directly coupled withthe spindle may operate over a relatively wide range of speeds-forexample, between 450 and 4,000 R. P. M.-and in combination therewith Iprovide reduction gearing whereby a spindle speed ranging between 57 and450 R. P. M. is obtained, the variation in speed resulting from theelectrical control of the motor.

A still further object of the invention is to provide an improveddriving arrangement as set forth above wherein a driving motor isprovided, which is capable'of a very fine speed variation and which isfree from clutches and conventional braking devices, the dynamic brakingof the motor serving to replace a conventional brake.

A very important object of the invention is to provide a machine capableof producing the work set forth above, which is free from vibration, andto this end I propose to preload the bearings of the machine spindle andhave a balanced driving connection between the prime mover and thespindle. r

In addition to the above mentioned and numerous other objects andadvantages, the invention contemplates an improved control arrangementafiording complete control of a machine carriage with respect to speed,such as feeding and rapid traverse, and also controlling the startingand stopping of said carriage in timed relation with the rotation of thespindle, and to this end I propose to provide a single control member,which may be manipulated to control all or some of the electrical primemovers, and also to control the feeding and rapid traverse movement ofthe carriage in a very simple and effective manner.

More specifically, the invention contemplates control mechanism whereinthe propelling devices for imparting rapid traverse and feeding movementto the machine carriage may be controlled sothat rapid traverse movementin opposite directions takes place independently of fluid supplied by afeed pump, or said rapid traverse may cooperate with the feeding fluidin propelling the machine carriage.

Another object is to provide an improved hydraulic control for amachine'of the type set forth above wherein a simple and single controldevice is employed for selectively controlling the operative functioningof the feed pump and a rapid traverse pump in such a manner that fiuid'from the feed pump may be circulated so as to render the sameinoperative or the prime mover therefor may be stopped during thefunctioning of the rapid traverse pump.

The foregoing and numerous other objects and advantages will be moreapparent from the following detailedkiescription when considered inconnection with the accompanying drawings, wherein---- Figure 1 is afront elevational view of a machine which is representatiye of oneembodiment of my invention;

Figure 2 is a fragmentary detail view of the hydraulic actuator formoving the tool supporting carriage;

Figure 3 is a fragmentary rear elevational view of the left end of themachine as viewed in Figure 1 to more clearly illustrate the location ofthe hydraulic unit with respect tothe adjacent headstock structures;

Figure 4 is a diagrammatic illustration to more clearly show the mannerin which the feedpump is synchronized with the main or headstock motor;

Figure 5 is a transverse horizontal sectional view of the headstock,particularly the spindle support, said view being taken substantiallyalong the line 55 of Figure 1;

Figure 6 is a fragmentary sectional view of the left end of the machine,said view being taken substantially along the line 6--6 of Figure 1,this view being shown to more clearly illustrate the manner in which theelectrical panels are conveniently housed beneath the main motor;

Figure 7 is a transverse sectional view of the headstock takensubstantially along the line 'i-.-'|, of Figure 5;

Figure 7A is a detail plan view of the electrical interlock controlshown in Figure 7;

Figure 8 is a transverse sectional view of the machine takensubstantially along the line 8-8 of Figure 1;

Figure 9 is a fragmentary vertical transverse sectional view of thetool-carriage taken substantially along the line 9-9 of Figure 8;

Figure 10 is a fragmentary sectional view taken substantially along theline Ill-I0 of Figure 9;

Figure 11 is a fragmentary plan view of the tailstock extremity of themachine, together with thetool carriage, said view being shown to moreclearly illustrate the functional and structural characteristics of themechanism employed for cutting tapers and the like;

Figure 12 is an enlarged horizontal fragmentary sectional view of thetailstock spindle, said view being taken substantially along the line|2--i2 of Figure Figure 13 is a fragmentary transverse sectional viewtaken along the line I3-l3 of Figure 12 to more clearly illustrate themarine]; in which lubricant is supplied to the tailstock;

Figure 14 is a perspective layout of the control bars adapted to beshifted by manipulating handles provided at the front side of themachine, said view being semi-diagrammatic in nature;

Figure 14A is a'detail disclosure of the bar compensating mechanismmounted on the front side of the machine bed immediately beneath thetailstock;

Figure 15 is an enlarged fragmentary vertical sectional view takensubstantially along the line i5-l5 of Figure 1 to more clearlyillustrate the interlocking control mechanism for the rapid traverse andfeeding pumps;

Figure 16 is a sectional view taken substantially along the line I 6-I 6of Figure 15, illustrating the vertically slidable plate whichcooperates toinsure-theneutral positioning of the main control valvewhen the main motor is activated;

Figure 17 is an enlarged rear elevational view of the hydraulic unit todisclose the manner in which the feed pump, main control valve, andSelsyn motor are. mounted thereon;

Figure 18 is a view taken from the left of Figure 1'! with a, portion ofthe hydraulic unit houscarriage and the hydraulic actuator-s for. thecross slide mounted thereon are controlled;

Figure 21 is a fragmentary transverse sectional viewv of the maincontrol valve taken substantially v along the line 2I2I of Figure 20;

Figure 22 is a similar transverse sectional view I taken substantiallyalong the line 22-22 of Figure 20; e

Figures 28 and 23A are electrical circuit diagrams illustrating themanner in'which the varsectional viewrof the gear pump shown in Figure24 .to more clearly illustrate the structural details thereof.

Referring now to the drawings more in detail wherein like numerals havebeen employed to designate similar parts throughout the various views, Ishall first describe generally certain main structures of a machinewhich is representative of one embodiment of my invention. The machineincludes a suitable bed 30, one end of' which supports a headstock 32and the other end 4,000 R. vP. M. The motor 40 drives an A. C.

generator 42 which will hereinafter be referred to as the Selsyngenerator.

A hydraulic unit designated generally by the numeral 44 (Figures .3,.17, and 18) is mounted at the rear of the bed and adjacentthe spindlesupport. This hydraulic unit includes a feed pump 46 which is drivenfrom a motor 48, which motor is electrically connected with the Selsyngenerator 42 and will be hereinafter referred to as-the Selsyn motor. Acasing 50 provides a [housing for -a suitable fluid reservoir 52 whichserves as a source of supply for a rapid traverse pump 54 .which isdriven from a prime mover a machine tool. Slidable on suitable ways 58provided along the upper intermediate portion of the bed 30 is a toolcarriage 60, which includes a bracket structure 82 for supportingvarious controls and 'a cross slide 64, which is adapted independentlyto shift transversely and with the carriage 60 longitudinally of a workpiece supported between the spindle 38 and the tailstock 34. Secured tothe underside of the carriage 60 is a cylinder 66 which forms an elementof a hydraulic actuator 68, later to be described, and serves to impartmovement to the carriage longitudinally of a supported work piece.

With the foregoing structures in mind, it should be'understood thatrotation at a selected speed is imparted to the spindle 38 by means ofthe main motor 40, and that the feed pump 46 is driven in synchronismwith the spindle through the agency of the above mentioned Selsyn drive,which includes the generator 42 and the motor 48. The feed pump 46 ishydraulically coupled with the actuator 68 and thus enables the earriage64 to be propelled at a feeding rate which is in synchronism with thespindle rotation. The rapid traverse pump 54 also operates at selectedintervals to impart rapid traverse to the carriage 64. I shall nowdescribe more in detail the various mechanisms of the machine tool orlathe.

Spindle support The spindle support or structure 36 is best shown inFigures 1, 5, and 7. The spindle 38 is mounted within preloadedanti-friction bearings I0 and I2. These bearings are, in turn, mountedwithin a casing or frame I4, which frame is secured and positioned uponthe bed 30 by suitable means 16. The bearing I0 is particularly designedto take up radial loads, whereas the bearing 12 in which the balls areencased in deeper raceways, is designed to take up thrust, as well asradial loads. Suitable collars or the like are employed to secure theball races in position, as clearly shown in Figure 5. Attention is alsodirected to the fact that the portion of the spindle 38 extending beyondthe end of the bearing 10 is provided, with a lubricant seal I8 toprevent the leakage of lubricant from within the casing I4. Rotation isimparted to the spindle 38 from the drive shaft of the main motor 40,which shaft, through the agency of a balanced coupling 82, connects witha stub shaft 84. This stub shaft 84 is mounted within an anti-frictionbearing 86 and carries a gear 88, which is keyed thereto. This gear 88is provided with teeth.90 adapted to mesh with internal companion teeth92 of a shif table clutch collar 94 (Figure 5). clutch member 84 isadapted to be shifted manually to the left through the agency of a yoke96, which is manually controlled by means of a lever 98 mounted on thetop of the casing I4 at the front side thereof (Figures 1 and 7).Suitable detents or members I00 yieldingly urged into association withthe teeth 92 serve to maintain said teeth inproper position ofregistration, said detents being shiftable within an aperture providedin a collar I02 carried by the spindle 38. An anti-friction bearing I04is carried upon the reduced extremity of the stub shaft 84 and forms abearing for one end of the supporting collar I02. When the clutch collar94 is shifted to the left into mesh with the teeth 90, a direct couplingor drive is established between the motor 40 and the spindle 38.However, this coupling cannot be established until a stop I 08 carriedby a back gear structure I 08 has been shifted rear- The wardly out ofthe path of the movement of the clutch member 94. The preloading andpositioning of the bearing 10 and I2 is such that at the end of thespindle 38 adjacent the work only radial thrust is experienced by thebearing 10, and this precludes the possibility of overheating thebearings. In other words, if these bearings were subjected to endthrust, as well as radial thrust, there would be apotential hazard ofoverheating. The danger of overheating is also decreased by reducing thearea contact due to preloacling of the bearing I0, as compared with thearea contact due to preloading of the bearing I2. .The bearing I2, beinglocated at a point removed from the end of the spindle which supportsthe work, is not subjected to radial loads which are as severe as theradial loads experienced by the bearing I0, and hence are adapted totake up thrust loads as well. The importance of these structural detailswill be more apparent when it is understood that the spindle 38 issubjected to speeds ranging from approximately 50 to 4,000 R. P. M., andfurther, that a 50 H. P. motor is constantly applying a load to thespindle.

The back gear structure I08 includes a frame I I0 which is pivotallysupported upon a member II2 (Figure 7) extending upwardly from thebottom of the frame 36. Mounted within the frame IIO upon preloadedanti-friction bearings H4 and H6 is a back gear shaft II8. A gear I20mounted upon the shaft H6 is adapted to mesh with the drive gear 88 whenthe frame I I0 is shifted toward the spindle and occupies the positionshown in Figures 5 and '7. In this position the gear 88 drives throughthe gear I20, and a smaller gear I22 mounted on the shaft II8 drives amain drive gear I24 carried by the spindle 38. In this manner thespindle may be functioning of the machine. .the gear supporting membersI28 are suitably driven at a speed which is lower'than the speed,obtained from the direct drive of the motor 40 thereto.

In this connection particular attention is directed to the fact that themain or larger drive gears I20 and I24 are preloaded so as to take upany distortion which might otherwise result from the tremendous speedsat which these gears are normally driven. It will be noted that the gearmember I20 is of an annular type which is mounted on a flange sectionI26 of the drive shaft II8. In placing the gear member I20 on thisflange, it is preloaded to such an extent as to take up any expansionwhich might otherwise result from centrifugal forces acting upon thegear. The gear I24 is likewise of annular form and is supported upon apair of rotary members I28. These members I28 are secured to an internalflange I30 of the gear I24 by means of bolts I32. Clearance is presentbetween the members I28 before clamping rings I34 are tightened againstsaid members. The tightening of these rings springs the members I26together at the hub, and sets up sufficient spring tension against theinner periphery of the gear I24 so as to take up any expansion of thegear resulting from centrifugal forces.

- These are important structural details because they contribute towardthe efiicient, accurate It will be seen that keyed directly upon thespindle 38.

Swinging-movementof the frame H0 is accomplished throu,h themanualmanipulation of a control handle I 36. When this control handle occupiesthe position shown in Figure 7 and a. solid line positionshown in Figure7A, an eccentric member I38 coupled with the handle occupies a positionwithin a companion bearing I40 in the frame IIO so as to urge the frameH0 into engagement with an adjustable screw or abutment I42. When thehandle I 36 is shifted to the dotted position shown in Figure 7A, thegears I 20 and I22 are moved out of mesh with their companion gears 88and I24, respectively.

As previously pointed out, the stop I06 moves rearwardly with the frameIIO, thereby enabling the clutch collar 94 to be shifted to the left(Figure 5). An electrical interlock, which will be more readilyunderstood from an examination of the circuit diagram shown in Figure23, is employed to prevent the functioning of the main motor 40 duringthe shifting of the back gears I20 and I22. It will be noted that thepivoted extremity of the handle I36 is provided with a. cam section I44.When the handle I36 occupies the solid line position shown in Figure 7A,a member I46 of a switch I46a is yieldably maintained in the positionshown. In this position the 'free extremity of the member I46 restswithin the low or recessed portion of the cam I44. In this position theswitch is closed. However, as the handle I36 is shifted to the left, thehigh surface of the cam I44 raisesthe member I46 and thus opens theswitch MM, and in this manner opens the circuit connected with the motor40, thereby preventing the starting of the motor until the handle hasbeen shifted to the dotted position. In other words, the switch I46cooperates with the handle I36 to provide an electrical interlockbetween the back gear and the spindle. It will be noted that the handleI36 is provided with a shiftable end section I48 which must be pulledoutwardly against a spring I50 to disengage a detent I52 in order toenable the handle to be shifted about the axis of the shaft I54 whichcarries the eccentric member I38.

Before proceeding with the description of other portions of the machine,attention is directed to the fact that when the motor 40 is coupleddirectly with the spindle 38, a balanced driving connection isestablished. In other words, there are no centrifugal forces tending tolaterally displace the rotating parts other than the normal centrifugalforces acting when balanced rotary parts are in motion. This balancedrotation is of the utmost importance in connection with high speedmachines or lathes of the type disclosed herein.

Lubricating system for headstock and gearing Attention is directed toFigure 19 wherein I have shown in a somewhat diagrammatic way the mannerin which the rotating parts of the headstock are continuouslylubricated. A suitable pump I56 is driven from the motor shaft through aflexible drive I58 and a speed reducing mechanism I60. The pump I56 isillustrated diagrammatically because the invention is not in any senselimited to any specific pumping device. It will suffice tosay that thepump I56 receives lubricant from a reservoir I62 and distributes saidlubricant through conduits or pipe lines'I64, I66, I68, and H0. Theconduit I64 supplies fluid to the bearing 86, and the conduit I66supplies fluid to the gearing or clutch member 94, the bearing I04 andparts associated therewith. The conduit I68 supplies lubricant to thebearing I2, while the conduit I10 supplies lubricant to the bearing I0.-In this manner the bearings of the spindle are constantly lubricatedstarting and stopping all of the electric motors.

ure 8).

during the rotation thereof and the possibility of overheating isreduced to a minimum.

A separate lubricating system is employed for the back gear structureinasmuch as this structure is employed only occasionally. This separatelubricating system includes a suitable pump such as a gearpump I12,which may be driven from the back gear drive shaft H8. This pump I12receives lubricant from a reservoir H4. The fluid from the reservoir I14passes through a conduit I I6 and thence through a filter I18 into thepump I12. From the pump I12 lubricant is delivered to the bearings H6and H4, and is also directed tothe meshing zone of the drive gears, asclearly indicated in Figure 19. The pump "2 also delivers lubricant tothe clutch member 84. It will also be understood that the spindleor'headstock casting or casing I4 serves as a fluid sump or reservoir,and that the fluid passes through the fllter or purilator I18. It willalso be understood that the lubricating supplying mechanism is such asto allow a measured amount of lubricant per revolution of the spindleinasmuch as the lubricating pump is in synchronism with the spindle. Byemploying my structure, thepossibility of causing the churning oflubricant within the casing I4, thereby developing excessive heat, ispositively precluded.

Machine carriage The machine carriage 64, as previously stated, includesa control supporting bracket 62- and a tool carriage or cross slide(proper) 64. The bracket 62 carries four control elements, namely, a

control handle I 88 which serves as a single control for the directionand speed of travel, and the starting and stopping of the machine parts,as will hereinafter be more fully' set forth. A second control handleI82 serves as a manual control for A hand-wheel I84 serves to control arheostat designated generally by the numeral I86, and thereby governsthe speed of rotation of the main motor 48. 'A hand-wheel I88 serves tocontrol the displacement of the feed pump 46. The functioning of theseelements will be more clearly understood when the cycle of operation ofthe machine is set forth in detail... To more clearly understand thedisposition and functioning of these control elements, reference is madeto the perspective showing in Figure 14.

The cross slide 64 is more clearly shown in Figures 8 to 10, inclusive.This cross slide includes a carriage or slide proper I88, which isslidable upon a carriage member I82, which member is mounted upontheguideways- 58. The slide I88 carries a tool I84 which is clamped inposition by means of screws I86. The alinement of the carriage memberI82 with respect to'the ways 58 may be adjusted by means of a clampingbolt I88 (Figure 8), which carries a clamp 288 at the lower end thereof,said clamp cooperating with the underside of the rear guideway 58 totake up wear and maintain proper alinement. The hydraulic actuatorcylinder 66 is supported by the carriage I82 and cooperateswith astationary pistol. 282 in effecting movement of the tool I84longitudinally of a supported work piece.

Manual transverse movement of the cross slide I88 is accomplishedthrough the agency of a hand-wheel 284, which hand-wheel is connectedwith a screw 286. The screw 286 is coupled with a pair of screw membersor nuts 288 and 2I8 (Fig- The degree of transverse movement of thecross-slide I88 is limited by a stop member 2 l2 by the mere exertion ofmanual -iorce.

(Figure 9), which is adapted to extend within a recess provided within amember 2. A screw 2 I6 when tightened against a plug 2 I8 is adapted topositively lock the cross-slide against transverse movement.

Attention is directed to the fact that the transverse movement of thecross-slide I88 is effected through the agency of a pair of actuatorpistons 228 disposed on opposite sides of the screw 286. These pistons228, through the agency of piston rods 222, are connected with a crossbar 224.

' In this connection it will be noted that the transverse movement ofthe cross slide I88 may be controlled through the agency of a roller226, which is adapted to bear against a cam member 228. This can be bestunderstood by referring to the plan view in Figure 11, wherein the cammember or bar 228 is shown more in detail. The cam member 228 (as shownin Figure 11) is provided with step portions, and these step portionsconform with the nature of the work piece upon which the tool I84 acts.In some instances a tapered cam bar may be found necessary. However, forpurposes of disclosure, one form of cam bar is shown in Figure 11.Through the agency of hydraulic actuator cylinders 228, the positiveshifting of the cross slide in combination with the cam bar 228 isinsured. Obviously in instances where merely cross feed is required, thecam bar 228 need not be employed.

Tailstock The tailstock 34 is best shown in Figures 1 and 12. Thisincludes a frame 238 which is mounted on the upper portion of the bed38. The frame or casing 238 provides a support for a sleeve 232. Thissleeve is adapted to be reciprocated within the casing 238 through theagency of a screw 234 and a nut 236 carried by the sleeve 232. Rotationof the screw is accomplished through the agency of ahand-wheel 238. Atail-stock center 248 is mounted within preloaded bearings 242 and 244.A suitable ball 246 within a nut 248 provides an end thrust bearing forthe center 248.

Particular attention is directed to the lubricating mechanism forthetailstock. In view of the high speed rotation of the work piece, I findit necessary to employ an automatic oiling arrangement, and this isclearly disclosed in Figures 12 and 13. A lubricant reservoir 258 ismounted at the rear side of the casing 238, and lubricant therefrom isdirected through various passages 252, 254, 256, and 258 to a springactuated member 268. This member 268 is slightly inclined with respectto the outer surface 262 of the enlarged portion of the center 248, asclearly shown in Figure 13.- This lubricant which is forced into theconfines of the member 268 passes out through a restricted opening 264in said member and is thus rubbed or wiped away by the surface 262. Theangle of inclination of the member 268 with respect to the surfacecontrols the amount of fluid dispatched to the bearings 242 and 244. Inthis manner the flow of lubricant to the bearings is controlled in avery eflfective and satisfactory manner.

The tailstock 34 being necessarily quite large and hence very heavywould be difficult to move Therefore, I provide a hook 266 (Figure 11),which is secured to the bottom portion of the casing or frame 238. A pin268 mounted on'the carriage member I82 is adapted to be received by thehook 266, therebyestablishing a coupling between said carriage memberand the tailstock. Thus the tailstock may be moved hydraulically inresponse to the hydraulic shifting of the tool carriage. A

Hydraulic unit I have previously referred in ageneral way to thehydraulic unit 44 mounted at the rear side of the bed 30 adjacent thespindle support 36. This unit 44 is so arranged as to be readilydetachable for purposes of repair, replacement and installation. Saidunit presents a compactly arranged group of elements such as the Selsynmotor 48, the feed pump 46, the rapid traverse pump 54, the rapidtraverse motor 56, and the oil reservoir 52. It will be seen that theSelsyn motor 48 drives the feed pump 46 through a vertical drive shaft214 (Figure 18), the lower end of which carries a gear 216 which mesheswith a companion gear 218 on a shaft 280. A gear 282 on said shaftmeshes with a gear 284, which, in turn, meshes with a gear 286. Thisgear 286 is coupled with the feed pump 46. I prefer to employ a feedpump of the type disclosed in my copending application, Serial No.430,867, filed Feb. 24, 1930, which has since matured into Patent No.1,989,117. In that application I have disclosed a plunger pump whereinfluid leakage from the high to the low pressure side of the system isprecluded, and therefore the pump is particularly adapted to be used ina closed hydraulic circuit. In view of the fact that the presentinvention is not limited to any particular pump structure, except assuch pump may enter into the general combination with other elements, Ido not deem it necessary to disclose the structural details of the pump.It will suflice to say that this pump is of the plunger pump type andthe displacement thereof is capable of being varied betweenpredetermined limits by turning a member 288 (Figure 17). This member isconnected with mechanism which varies the eccentricity of the drivingdevice (not shown) within the pump, and thus varies the stroke of thepump pistons. In this way the displacement of the pump iscontrolledwithin predetermined limits. As previously pointed out, the hand-wheel188 is coupled with the adjusting mechanism of the pump 46 for thepurpose of varying the rate of feed of the carriage. This will presentlybe more clearly set forth in connection with the description of theoperating cycle of the machine. In addition to supporting the parts Ireferred to, the hy; draulic unit also supports a main control valve;mechanism 2911 later to be described.

Hydraulic system of control Before taking up in detail the manner inwhich the movement of the machine parts may be manually as well asautomatically controlled, I wish to call attention to the hydrauliccircuit whereby the operative functioning of the feed pump 46 and therapid traverse pump 54 with respect to the hydraulic actuator 68, isselectively controlled. The main control valve mechanism 298 justreferred to includes a sultablevalve casing 292, and this casing carriesa reciprocable main valve member 294 and what I prefer to call a feedcontrol valve member 296. It will be noted that the valve member 294 asshown in Figure 20 occupies its central or neutral position. When thevalve member occupies this position, fluid from the rapid traverse pump54 is directed through a conduit or line 298 into a valve port 300. Fromthis point said fluid passes through a radial valve port 302 and thencethrough a longitudinal passage 304 into an end chamber 306. This endchamber 306 communicates through a return conduit or line 308 and arestricted orifice 310 with the reservoir 52. Thus fluid from the gearpump is circulated back to the reservoir against the pressure which isdeveloped as a result of the restricted orifice 310. At this point itshould also be understood that the pressure thus established is exertedwith equal force at each extremity of the valve member 294, therebymaintaining said valve member in absolute balance.

If, under the circumstances set forth above, the feed pump 46 is beingdriven through the agency of the mechanism previously described, fluidwill pass through-the pump into a conduit or line 312 and thence into astarting and stopping valve mechanism designated generally by thenumeral 314. This mechanism 314 includes a valve casing 316 and a valvemember 318 'reciprocable therein. When the valve member 318 ismaintained through the agency of a spring 320 in the position shown inFigure 20, fluid from the line 312 is adapted to circulate through aperipheral valve port 322 back to the intake side of the feed pump 46through a conduit or line 324. Thus the feed pump is functionallyinoperative for propelling purposes. In this connection it will beobserved that the left end of the casing 316 is coupled with the valveport 300 through a conduit 326, and that the pressure within the conduitis not suflicient to overcome the force of the spring 320.

Assume now that the valve member 294 is slightly shifted to the right.This causes a restriction in the radial port 302 and thus an increase influid pressure takes place within the side areas 328 of the valve member284. This increase in fluid pressure is transmitted through the conduit326 and thus acts to urge the-valve member 318 to the right against theaction of the spring 320. Also, the slight shifting of the valve member294 to the right causes an aperture 330 to be brought into communicationwith fluid at higher pressure, and thus fluid pressure is transmittedthrough a passage 332 to a cham'- ber 334 at the right end of the feedcontrol valve member 296. This causes the valve member 296 to beretained in the left position as shown in Figure 20. Fluid forced from achamber 336 at the left end of the valve member 296 is free to flowthrough a passage 338 and thence into the valve chamber 306. The slightshifting of the valve member 294 is not suflicient to affect thecirculation of the fluid from the gear pump 54, but is suificient tocontrol the shifting of the feed control valve 296. Under the conditionsjust described, fluid under high pressure from the feed pump 46 isdirected through the starting and stopping valve mechanism 314 into aconduit or line 340, a valve passage or port 342, a radial port 344 inthe valve member 296, a longitudinal passage 346, a radial passage 348,and thence through a valve port 350 and a conduit 352 to the right endof a hollow piston rod 354 coupled with the piston 202. An aperture 356permits fluid to enter the right chamber 358 in the cylinder 66, therebycausing the carriage 60 to move at a feeding rate to the right.

To obtain movement of the carriage at a feeding rate to the left andassuming thatthe valve member 294 occupies the neutral or startingposition referred to above, it is only necessary to urge the valvemember 294 slightly the left.

"By so doing, the same restriction takes place within the radial valveport 382 so as to establish an increase in fluid pressure within theside areas 328, and thus cause the valve member 3I8 to be urged to theright. However, this slight shifting of the valve member 294 to the leftcauses fluid under increased pressure to communicate with a valvepassage 368. Thus the increase in fluid pressure is transmitted throughthe passage 338 to the left end chamber- 336, thereby causing the feedcontrol valve 296 to be urged to the right against a stop 362. In thisposition fluid from the feed pump 46 is directed by a radial port 364 ofthe valve member 296 into a valve port 366 and thence into a conduit 368communicating with the left end of the hollowconnecting rod 354. Fluidpasses through an aperture 318 into the left chamber 312 of the actuatorcylinder 66, thereby causing the machine carriage to be urged at afeeding rate to the left.

Before explaining the manner in which rapid traverse and feedingmovements are selectively controlled, attention is directed to a valvemechanism 314 (Figure which serves to control the direction of fluiddelivered to the crossslide actuator pistons 228. It willbe noted thatfluid pressures experienced'within the chambers 358 and 312 of theactuator cylinder 66 may be transmitted through conduits 316 and 318,which connect with ports 388 and 382, respectively, in a valve casing384. A valve member 386 within the casing 384 is manually shiftabiethrough the agency of a control handle 388, and when said valve memberoccupies the central or neutral position shown in Figure 20, no fluidpressure is transmitted to the actuator pistons 228. In other words,these pistons are locked in position. However, if the valve member 386is shifted rearwardly and fluid pressure is established within theconduit 318, the actuator pistons will be moved forwardly. If, undersuch circumstances,

I tion of movement of the pistons 228 may be very convenientlycontrolled.

Assume now that instead of -moving the valve member 294 slightly to theleft as previously described, said member is moved completely to theleft so as to bring the side areas 328 into communication with the valveport 366. Under such circumstances fluid from the gear pump 54 deliveredto the side areas 328 is directed to the left end chamber 312 of theactuator cylinder 66, and fluid from the right end of said cylinderpasses outwardly through the conduit 352 and thence into the valve port358. Likewise, when the valve member 294 occupies its extreme rightposition, fluid from the rapid traverse .pump 54 is delivered to theright end of the cylinder 66. Thus far I have referred only to themanual control of the valve member 294, but it will be obvious that saidcontrol may be fully automatic, and this is accomplished through theagency of suitable dogs 398, 392, and 394'adjustably carried upon guidebars 396 mounted on the front side of the bed 38.

, Automatic control referring to the perspective disclosure in Fig-v ure14 in conjunction with the hydraulic circuit of Figure 20. The controlhandle I88 which is mounted on the front side of the control supportingbracket 62 (Figure 15) is rotatable with and mounted upon a sleeve 398.The handle is pivotally carried by a member 488, which is mounteddirectly upon the sleeve 398 and is keyed thereto. The inner extremityof the sleeve 398 supports a disk 482 having ears 483, which ispositioned adjacent a bevel gear 484 formed integral with the sleeve398. A pin 486 carries a disk 488 and this disk carries a pair ofoppositely disposed registering pins 4I8 which are adapted to registerwith and engage within companion apertures provided in the disk 482. Thepin 486 is normally urged to the left (Figure 15) through the action ofa coil spring 4 I2, thereby maintaining an interlock between the disk482 and the gear 484. To disengage the connection between the sleeve 398and the disk 482, it is only necessary to swing the handle I98outwardly, namely, to the left (Figure 15), thereby urging the pin 486inwardly and causing the pins M8 to be withdrawn from the complementaryapertures in the disk 482. The driving connection of the sleeve 398 andthe gear 484 with the handle is always maintained, and hence movement ofthe handle I88 about the axis of the sleeve 398 will positively effectthe shifting of the main control valve member 294, regardless of thedisengagement of the pins 4I8 from the disk 482..

The foregoing can be best understood by referring to Figure 14 whereinit is shown that rotation of the gear 484 causes rotation of a companiongear 4 I4, which is slidably mounted upona square rod 4I6. The leftextremity of this rod 6 carries a segment 4I8 which meshes with a rackbar 428. This rack bar 428 also meshes with a second segment 422connected with a rod 424. The rod 424 is coupled with an actuatingfinger or member '426, which makes a slotted connection or coupling withthe left end of the valve member 294, as clearly shown in Figure 20.Thus movement of the control handle I88 to the left causes thevalvemember 294 to be shifted to the right (Figure 20), and likewise,movement of said handle to the right (Figure 14) causes said valvemember to be shiftedto the left (Figure 20) When the handle I88 occupiesits vertical position as shown in Figure 1, the valve member 294 isin.neutral. It will thus be apparent that the handle I88 serves as themanual control for the valve member 294. Automatic control of said valvemember is governed by means of the dogs 398, 392, and 394 previouslyreferred to, which dogsare adapted to engage a pin or finger 428 carriedat the lower extremity of a vertically shiftable rack bar 438. The upperend of this bar meshes with a quadrant or gear segment 432 carried bythe square rod 4I6. Thus it will be apparent that the shifting of therack bar 438 and the consequent shifting of the main control valve 294may be selectively and automatically controlled by the aforementioneddogs. Any automatic cycle of operation can be obtained by the use ofproper dogs disposed along the supporting bars 396. It will also benoted that the roller 428 carries a rack bar 434 which is adapted toshift a lever 436 of a rapid traverse control switch 438. When thecontrol handle I 88 occupies its central or neutral position, the roller434 engages the member 436 and thereby maintains the switch 438 open. Inother words, under these conditions the rapid traverse motor 56 isdisconnected from the circuit, and hence the rapidtraverse pump 54 isinactive. However, when the handle I80 is moved so as to shift the maincontrol valve 294 to either of its rapid traverse positions, the roller434 moves away from the member 436, thereby enabling the switch 438 toautomatically close.

The purpose for having the disk 402 provided with the ears 403 (Figure16) is to cause said disk to be automatically shifted to, the central orneutral position through the action of a vertical plate or bar 440. Thisplate 440 is provided with rack teeth 442 which mesh with a gear segment444 carried by a square rod 446 (Figure 14) The left extremity of thisrod 446 is connected through a bell-crank 448, a link 450, and a secondbellcrank 452 with a switch mechanism 454, which is designed to controlthe disconnection and connection of the motbrs including the motor 40.Manual control of rotation of the rod 446 is accomplished bymanipulation of the handle I82. This handle acts through a pair of bevelgears 456 and 458 to control the rotation of the rod 446. Thus, when thehandle I82 occupies the vertical. position shown in Figure 14, theswitch mechanism 454 is opened so as to disconnect the motors from theline and the plate 440 occupies its uppermost position. In this positionthe ears 460 engage the companion ears 403 of the disk 402, therebysecuring said disk against rotation.

The importance of this construction will be more readily appreciatedwhen it is understood that, if the main control valve member 294occupied a rapid traverse or feeding position when the switch mechanism454 was closed, it might cause considerable damage. In other words, itis desirable to have a safety mechanism which will insure thepositioning of the main control valve in neutral atthe time the switchmechanism 454 is to be closed. Assume, for example,

that an operator shifted the control handle I80 so as to effect a rapidtraverse movement of the tool carriage and, before returning the handletoneutral, opened the switch 454 by the manual manipulation of thehandle I82 so that he could leave the machine. Upon returning to themachine, it is quite possible that he would forget that the main controlvalve was left in rapid V traverse or feed position and considerabledamage might resultif the motors were cut in. However, by employing theplate 440, the main control valve is always returned to neutral when themotors are cut out provided, of course, that the interlock between thedisk 402 and the bevel gear 404 is maintained by the pins 4I0. Thus, ifthis interlock is maintained and the plate 440 moves upwardly, theengagement of the companion ears 403 and 460 causes theautomatic-positioning of the handle I80, and consequently the maincontrol valve 294 in neutral. A vertical slot 462 cooperates with a pinorroller 464 in limiting and uiding the movement of the plate 440. Theroller 464 is carried by a pin 466, as clearly shown in Figure 15.

From the foregoing description it will be apparent that if the controlhandle I80 is urged outwardly, namely, to the left (Figure 15 so as todisengage the pins 4I0 from the disk 402, the main control valve 294 maybe shifted, even though the plate 440 remains in its uppermost positionas shown in Figures 14 and 16.

It will also be noted that with the above described control mechanismthe main motor 40, and consequently the Selsyn drive mechanism whichpropels the feed pump, may be electrically disconnected from the systemwithout. affecting synchronized and varies with the speed of the tweenthis bearing and a nut 490 is a coiled spring functioning of the rapidtraverse motor 56. In

other words, rapid traverse movement of the carriage may take placewhile the main spindle driving and feed pump motors are inactive. Aspreviously described, in connection with the hydraulic circuit shown inFigure 20, the main motor 40, as well as the Selsyn drive, may beelectrically connected in the circuit during the functioning of therapid traversemotor without causing the feed pump to operatively effectthe hydraulic actuator 68. This is accomplished by the use of thestarting and stopping valve mechanism 3" previously described whereincirculation of the feed pump 46 1s accomplished. This affords at leasttwo types of independent control of the rapid traverse and feedingfluids, and the invention also contemplates other mechanisms whereby theelectrical control of the Selsyn motor maybe accomplished in the samemanner as the electrical control of the rapid traverse motor 5'6. Aspreviously pointed out, manipulation of the hand-wheel I88 serves toeffect the control of the displacement of the feed pump 46, and this isaccomplished through a pair of bevel gears 468 and 410, the latterslidably mounted upon a square shaft 412. This shaft 412 has a gearedconnection with a transversely extending shaft 414 which is connectedwith a valve adjusting rod or shaft 416 through the agency of gears'418-480 and a flexib1e drive 482. Thus manipulation of the hand wheelI88 serves to vary the speed of the hydraulic actuator 68 by varying thedisplacement of the pump 46. As previously pointed out, the speed of thefeed pump 46 is main motor 40, and the displacement control simplyaffords additional adjustment in instances where such adjustment isrequired.

The hand-wheel I84 is connected with a square rod 484 which serves tooperate the rotary rheostat mechanism I86, and bythis adjustment thespeed of the main motor 40 may be varied within predetermined limits.This affords a still further method of speed adjustment in addition tothe fluid displacement control just described. The right extremity ofthe rods M6, 446, 412, and 484 are mounted within a support 486 (Figure14A). Each bar is supported by an antifriction thrust bearing 488, andinterposed be- An adjustable abutment screw 494 is also This 492.employed, as clearly shown in this figure.

supporting device 406 serves as a compensator to take care of anylongitudinal shifting or changes in the rods. I

The automatic and sudden reversal of the main control valve member 294is accomplished by a reverse control valve member 496 (Figure 20). Thisvalve member is normally held in the position shown in Figure 20 bymeans of a coil spring 498 which is housed within a cap member 500. Inthis position the valve member 496 prevents the flow of fluid from anend chamber 502 through a passage 504. However, when the fluidpressure-within an end chamber 506 resulting when the actuator reachesthe limit of its advancing movement, is sufiicient to shift the valvemember 496 against the action of the 502 enables the normal pressure ofthe balancing fluid within thechamber 306 to suddenly urge the valvemember 294 to the right, thereby causing a rapid reverse travel of thecarriage 60.

Electrical controls Attention is directed to the fact that the headstocksection of the bed 30, as shown in Figure 6, provides a mountingforelectrical panels designated generally by the numeral i6. These-panels are shown diagrammatically in Figures 23 and 23A and areindicated in a general way as panels and the like when used with machinetools have been very cumbersome and havenot been readily accessible forpurposes of repair and replacement. It will be noted that resistors 518are' mounted to one side of the bed in a very convenient position andare not in the way of the operator. All of the panels, resistors, andthe like mountedin 'the chamber 520 beneath the main motor, arethoroughly ventilated by the provision of ventilator covers 522. Whilethese are structural details, such details cooperate to render themachine most practical in the field and materially contribute toward itsusefulness.

It will also be noted that complete manual control of the machine may beaccomplished by a switch mechanism 524 equipped with a series of buttons(Figures 1 and 23). In some instances it may be desirable toelectrically control the machine by manual manipulation of thesebuttons. In addition to the electric motors thus far described, I alsoprovide an electric motor 526, which is mounted at the right end of thebed 30 (Figure 1), and this motor serves to drive a coolant pump. Fluidfrom this pump (not shown) ventional in design and are merelyelectrically coupled so as to bring about-the cycle of operation andcontrol previously set forth. In Figure 4 I have in a somewhatdiagrammatic manner disclosed the electrical coupling between the mainmotor and the feed pump through the Selsyn drive, and have disclosed thefeed pump operatively coupled with the hydraulic actuator. Thisillustration is presented to simplify an understanding of thesynchronized drive between the rotation of the spindle and thetranslation of the tool carriage.

Attention is now directed to the disclosure of a modified feed circuitshown in Figure 24. In this circuit I have shown the rapid traverse pump54 connected in series with the feed pump 46, both of said pumps beingconnected in a closed circuit with the actuator 68. This particulararrangement is such as to enablea very small displacement of fluid fromthe feed pump 46 at relatively high pressures. I have found that when aconfined fluid body, such as a body of oil, is subjected to relativelyhigh pressures-for example,

a pressure of 900 pounds-said fluid experiences a molecular change orcompression. In other words, the fluid is preloaded. The eflect of thispreloading or the fluid due to the high pressures introduces noappreciable error when fluid is being displaced at a normal rate fromthe feed pump. However, itthe fluid displacement. is very small, inorder to obtain slow feeding movement of a carriage,'the preloading ormolecular change in the fluid is sumcient to cause an appreciableslippage to take place. In other words, if the stroke of the pistons inthe feed pump is very small, the volume delivered by the piston iscorrespondingly small, and hence it may be that the change orcompression experienced as a result of the high pressure would, undercertain circumstances, give no actual fluid delivery at the dischargeside of the pump.

To overcome the above mentioned difficulties, I propose to couple thepump 54 with the intake of the feed pump 46 so as to charge the feedpump at a relatively high pressure, say, for example, 900 pounds. Assumethat it is necessary to obtain a 1,000 pound pressure at the dischargeside of the feed pump to propel the actuator. Then there will exist adifferential of only 100 pounds between the charging fluid and the fluiddelivered by the feed pump. Obviously the effect of this difierential of100 pounds would be insufllcient to introduce any appreciable error.This shouldbe compared with a system wherein the fluid delivered to thefeed pump is at a relatively low pressure, which must be built up sayfrom 200 pounds to 900 pounds. Under such circumstances this increase inpressure might be suflicient to introduce appreciable errors whenrelatively small displacement of the feed pump is desired. In fact, byemploying the arrangement shown in Figure 24, a movement of the carriageat the rate of or of an inch per minute may be obtained. In thisconnection I call attention to the fact that the pump 54 may be 01' thetype shown in my Patent No. 1,912,737, wherein a pair of gears 528 and530 rotate within a casing .532. Fluid from the meshing teeth isdirected through radial passages I84 into a valve port 536. Assume thatthe gears are rotating in the direction indicated by the arrows and thatfluid is .introduced within the chamber 538 and is discharged throughthe chamber 540. The pressure within the chamber 540 may be maintainedat a predetermined point, and fluid may bypass back through the radialpassage 534, the valve port 536 to the intake chamber 538. Theadjustment of the valve member 542 will serve to vary the degree ofbypassing and hence the amount of pressure developed within thedischarge chamber'540.

Referring to Figure 20, it will be observed that I provide bleedpassages 544 and 546 in the valve member 294 in order to take care ofany slight leakage which may occur in the packings of the hydraulicactuator 68 and other associated parts.

However, these bleed passages are not employed for the purpose ofcounteracting leakage in the feed pump 46 inasmuch as I prefer to employa pump wherein no slippage or leakage of any appreciable amount occurs.Each of these bleed passages opens into a longitudinal passage 548,which is best shown in Figure 22. A longitudinal passage 550 (Figure2-2) maintains communication between the chambers at the oppositeextremities of the valve member 294.

By having the fluid motor or actuator cylinder 66 iormed integral withthe carriage I92, a very

